I'm extremely new to using Firebase cloud functions, and I am struggling to find the error in my code. It is supposed to trigger on a firestore write and then copy that document into all of the user's feeds who follow that user who posted.
My current code is below:
exports.fanOutPosts = functions.firestore
.document('posts/{postId}')
.onCreate((snap, context) => {
var db = admin.firestore();
const post = snap.data();
const userID = post['author'];
const postCollectionRef = db.collection('friends').document(userID).collection('followers');
return postCollectionRef.get()
.then(querySnapshot => {
if (querySnapshot.empty) {
return null;
} else {
const promises = []
querySnapshot.forEach(doc => {
promises.push(db.collection('feeds').document(doc.key).collection('posts').document(post.key).update(data));
});
return Promise.all(promises);
}
});
});
So this successfully deploys to Firebase, but it receives this error when a document is created:
TypeError: db.collection(...).document is not a function
at exports.fanOutPosts.functions.firestore.document.onCreate (/workspace/index.js:22:60)
Line 22 is const postCollectionRef = db.collection('friends').document(userID).collection('followers');
I am unsure why this line is causing errors with the .get, but if anyone could point me in the right direction it would be much appreciated!
Given that this is the nodejs API, you'll want to use doc() instead of document(). Other languages might use document().
I found this info via the Admin SDK on CollectionReference https://googleapis.dev/nodejs/firestore/latest/CollectionReference.html
According to the reference, the collection should be defined as the following:
const postCollectionRef = db.collection(`friends/${userId}/followers`);
Using template literals will allow you to dynamically add variables into the collection ref.
I would also take a look into the else logic to use template literals within your return statement.
Related
I observed a huge amount of read on my firebase console and I was wondering if this might come from my "referral function".
This function works perfectly fine but I was wondering whether or not this function could end up with a crazy load of read in case of app scaling.
My question: does this function imply that every time a user comes in, it will account for a number of read equivalent to the number of users in my collection ?
Thus, as this function is an onUpdate, will it redo the job every time a document is updated ?
I would not mind some resources on the topic because I found it unclear on Firebase's website.
I hope my questions are clear!
Thank you very much!
export const onReferralInfoUpdate = functions.
firestore.document('users/{userUid}')
.onUpdate(async (change, context) => {
const before = change.before.data();
const after = change.after.data();
const currentUserUid = after["uid"];
if (before.godfather_code == after.godfather_code){
console.log('Text did not change')
return null
}
const godfatherUserSnapshot = await db.collection('users').where("referral_code", "==", after.godfather_code).get();
const godfather = godfatherUserSnapshot.docs[0].data();
const godfatherUid = godfather["uid"];
const userRef = db.collection('users').doc(after.uid);
const godfather_code = after.godfather_code
await userRef.update({godfather_code})
console.log(`the text before was >> ${before.godfather_code} << and after is ${after.godfather_code}` )
let batch = db.batch();
const updateGodfather = db.collection('users').doc(godfatherUid);
batch.update(updateGodfather, {
reward: admin.firestore.FieldValue.increment(100),
godChildUid: admin.firestore.FieldValue.arrayUnion(currentUserUid),
});
return batch.commit();
});
Yes, the where("referral_code", "==", after.godfather_code).get() will fetch all the documents matching the query every time onUpdate() function triggers and you'll be charged N reads (N = number of matched documents). The Admin SDK doesn't have any caching like Client SDKs.
Does this function imply that every time a user comes in, it will account for a number of read equivalent to the number of users in my collection ?
Not numbers of documents in the users collection, only the documents matching your query as mentioned.
I am writing a few triggers who work on a firestore databse of movies and users.
in this trigger' I am trying to display a new user the top rated movies in a list of genres he chose. for that I have an array of his favourite genres, and I want to query the database inside a foreach loop:
import * as functions from 'firebase-functions';
import { __values } from "tslib";
import * as admin from 'firebase-admin';
admin.initializeApp();
const films = admin.firestore().collection("Films");
export const new_user_recommend = functions.firestore
.document('/Users/{email}')
.onCreate((snap, context) => {
const new_user = snap.data();
if(new_user){
const new_email = new_user.email;
const favourite_genres = new_user.favourite_genres;
let film_id_arr: string[] = new Array();
favourite_genres.forEach((genre: string) => {
films.where('genres', 'array-contains', genre).orderBy('avg_rating', 'desc').limit(5).get()
.then((list_book: any)=>{
list_book.forEach((element: any) => {
const film_element = JSON.parse(element.data());
film_id_arr.push(film_element.data().id);
});
return film_id_arr;
})
.catch((error: any)=>{
console.log(error);
console.log("Error loading films");
});
});
}
return 0;
});
the problem is I always get the error message in the catch clause (so for each genre in the array I get the error message). I double checked to make sure the strings in the array are the same as the strings who might be written in 'genres' field for each film document.
This lead me to believe my query is somehow incorrect. Is that the case?
I edit to add some important details. the exact error I get is "Could not load the default credentials", So would that indicate a problem with user authentication rather than the query itself?
After quick search it seems that your problem is that you're using firebase-admin without providing valid credentials website.
Atleast that's how it seems judging from the error code.
The credentials for deployed functions are necessary only for firebase-admin but not for firebase-functions.
When I create a new document in the note collection, I want to update the quantity in the info document. What am I doing wrong?
exports.addNote = functions.region('europe-west1').firestore
.collection('users/{userId}/notes').onCreate((snap,context) => {
const uid = admin.user.uid.toString();
var t;
db.collection('users').doc('{userId}').collection('info').doc('info').get((querySnapshot) => {
querySnapshot.forEach((doc) => {
t = doc.get("countMutable").toString();
});
});
let data = {
countMutable: t+1;
};
db.collection("users").doc(uid).collection("info").doc("info").update({countMutable: data.get("countMutable")});
});
You have... a lot going on here. A few problems:
You can't trigger firestore functions on collections, you have to supply a document.
It isn't clear you're being consistent about how to treat the user id.
You aren't using promises properly (you need to chain them, and return them out of the function if you want them to execute properly).
I'm not clear about the relationship between the userId context parameter and the uid you are getting from the auth object. As far as I can tell, admin.user isn't actually part of the Admin SDK.
You risk multiple function calls doing an increment at the same time giving inconsistent results, since you aren't using a transaction or the increment operation. (Learn More Here)
The document won't be created if it doesn't already exist. Maybe this is ok?
In short, this all means you can do this a lot more simply.
This should do you though. I'm assuming that the uid you actually want is actually the one on the document that is triggering the update. If not, adjust as necessary.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
const db = admin.firestore();
exports.addNote = functions.firestore.document('users/{userId}/notes/{noteId}').onCreate((snap,context) => {
const uid = context.params.userId;
return db.collection("users").doc(uid).collection("info").doc("info").set({
countMutable: admin.firestore.FieldValue.increment(1)
}, { merge: true });
});
If you don't want to create the info document if it doesn't exist, and instead you want to get an error, you can use update instead of set:
return db.collection("users").doc(uid).collection("info").doc("info").update({
countMutable: admin.firestore.FieldValue.increment(1)
});
It seems I can't find a proper way to use the read/write functions for admin in the Cloud Functions. I am working on a messaging function that reads new messages created in the Realtime Database with Cloud Functions Node.js and uses the snapshot to reference a path. Here is my initial exports function:
var messageRef = functions.database.ref('Messages/{chatPushKey}/Messages/{pushKey}');
var messageText;
exports.newMessageCreated = messageRef.onCreate((dataSnapshot, context) => {
console.log("Exports function executed");
messageText = dataSnapshot.val().messageContent;
var chatRef = dataSnapshot.key;
var messengerUID = dataSnapshot.val().messengerUID;
return readChatRef(messengerUID, chatRef);
});
And here is the function that reads from the value returned:
function readChatRef(someUID, chatKey){
console.log("Step 2");
admin.database.enableLogging(true);
var db;
db = admin.database();
var userInfoRef = db.ref('Users/' + someUID + '/User Info');
return userInfoRef.on('value', function(snap){
return console.log(snap.val().firstName);
});
}
In the firebase cloud functions log I can read all console.logs except for the one inside return userInfoRef.on.... Is my syntax incorrect? I have attempted several other variations for reading the snap. Perhaps I am not using callbacks efficiently? I know for a fact that my service account key and admin features are up to date.
If there is another direction I need to be focusing on please let me know.
I'm using Cloud Functions for Firebase, and I'm stuck with what seems to be a very basic operation.
If someone adds a post, he writes to /posts/. I want a portion of that post to be saved under a different node, called public-posts or private-posts, using the same key as was used in the initial post.
My code looks like this
const functions = require('firebase-functions');
exports.copyPost = functions.database
.ref('/posts/{pushId}')
.onWrite(event => {
const post = event.data.val();
const smallPost = (({ name, descr }) => ({ name, descr }))(post);
if (post.isPublic) {
return functions.database.ref('/public-posts/' + event.params.pushId)
.set(smallPost);
} else {
return functions.database.ref('/private-posts/' + event.params.pushId)
.set(smallPost);
}
})
The error message I get is: functions.database.ref(...).set is not a function.
What am I doing wrong?
If you want to make changes to the database in a database trigger, you either have to use the Admin SDK, or find a reference to the relevant node using the reference you've been given in the event. (You can't use functions.database to find a reference - that's used for registering triggers).
The easiest thing is probably to use event.data.ref (doc) to find a reference to the location you want to write:
const root = event.data.ref.root
const pubPost = root.child('public-posts')